S-91259A810 1/2"-13 ASME B18.3, ASTM A574 Shoulder Screws

Key Features & Benefits at a Glance

• Exceptional Load-Bearing Performance: With a tensile strength of 140,000 psi and shear strength of 84,000 psi, this shoulder screw ensures reliable operation under high-stress conditions, reducing the risk of failure in demanding applications.
• Superior Corrosion Resistance: The black oxide finish provides a durable protective layer, enhancing longevity and maintaining integrity in harsh industrial environments.
• Precise Alignment and Stability: Featuring a 4" shoulder length with tight tolerances (±0.005"), it offers accurate component positioning and minimizes misalignment, improving assembly efficiency.
• High Thread Reliability: Class 3A thread fit and 1/2"-13 UNC coarse threads deliver secure fastening with reduced loosening, ideal for vibration-prone setups.
• Enhanced Grip and Easy Installation: The knurled socket head with a 5/16" hex drive allows for firm tool engagement and straightforward tightening, speeding up maintenance and assembly processes.
• Robust Material Durability: Made from alloy steel with Rockwell C32 hardness, it withstands wear and tear, ensuring long-term performance in repetitive or heavy-duty use.
• Compliance and Safety Assurance: Meets ASME B18.3 standards and is RoHS 3/REACH compliant, guaranteeing quality and environmental safety for global industrial applications.

Professional Applications & Engineering Value

This alloy steel shoulder screw is engineered to address critical challenges in precision machinery and industrial assemblies, where misalignment and component slippage can lead to operational failures. The 4" shoulder length with minimal tolerances ensures exact axial alignment for rotating parts like bearings and pulleys, reducing friction and wear. The black oxide finish combats corrosion in humid or abrasive settings, while the 1/2"-13 UNC coarse threads and Class 3A fit provide a secure, vibration-resistant connection in equipment such as conveyor systems and automotive jigs. By integrating high tensile and shear strength, it supports heavy loads in robotics and manufacturing fixtures, enhancing reliability and reducing downtime for B2B clients seeking durable, standards-compliant fastening solutions.

Specification Summary & Compliance

This shoulder screw adheres to precise dimensional standards, including a Class 3A thread fit for superior engagement and a shoulder diameter tolerance of -0.004" to -0.002" with length tolerance of ±0.005" to ensure accuracy. It conforms to ASME B18.3 manufacturing specifications and is compliant with RoHS 3 (2015/863/EU) and REACH (EC 1907/2006) regulations, affirming its safety and environmental responsibility for industrial use.